Prusa i3 Build

Neil

Thanks for documenting the Turbocad method. I made some "temporary" 22mm OD 9TPI buttress form nuts in 2013 in PLA. Being a lager thread got away with 0.3mm layer. I put a picture in an album. Needed to make another batch and forgotten the "revolve" and edit in the properties tree to make a spiral method. THKS.

Peter

If you are looking for acetone try your local fibreglass supplier. For those of you from Essex there is one at Canvey Island. https://www.cybglassfibre.co.uk/shop/products/acetone

Hope this is of use

Graham

Acetone can be bought in bulk from any fibreglass supplier, I recently bought 25l of 'Cure-it' acetone for when I re-covered one of my flat roofs with fibreglass.

Neil, thank you for explaining your technique. Unfortunately this won't work for me as Turbocad is Windows/Mac and I use Linux. I would be very interested to know if anyone here has achieved the same result in FreeCad.

Sorry I don't have time to check if this produces what you need but there are a number of Macro add-ons for FreeCAD. Screw-Maker, which I think is here, optionally generates real threads, though metric only. I find the option to produce a screw-tap, (i.e a length of studding) most useful. You can use them to make threaded holes using the Part Workbench to position the thread body in something else before subtracting it.

Despite having the excellent Fusion360 as well, I rather like FreeCAD and prefer it for modelling single parts. At the moment, FreeCAD's biggest shortcoming is the absence of an Assembly Workbench, which is a must have for many purposes. I hope they get one out soon.

Dave

I must admit I am surprised that very few of 'our' suppliers sell 3D printers (Axminster do the Dremels).

Aside from selling to existing hobbyists it seems an ideal way of encouraging 'makers' to cross over into engineering.

Neil

I really liked the look of the prusa I3 and especially after having seen their recommendation in the magazine, I think this is having a knock-on effect, because I can't get hold of one.

I asked the guy who runs the site when a new one would be relisted and he said Wednesday evening, I didn't get paid till Thursday morning and it appeared as though he hadn't done it,

so I asked him again on Friday and he replied that they get sold so quickly you have to be within minutes of the listing to have a chance. So he said the only thing I could do would be to wait until next week to get another chance at bidding for one.

I politely refused so unfortunately I'm having to look at other models simply because of this supply problem.

It might be a bit of a moan but it just goes to show it doesn't matter how good the product is if I cant get hold of it!

In the end I've bought a sintron kit, so I guess i'll see what this is like and see it as a chance to review a different model. 

Michael W

Edited By Michael-w on 19/05/2017 11:53:57

I think the problem is they print the PLA parts themselves, so they are probably listing them as soon as they get a complete set of parts!

Having some grief at the moment with PLA that just doesn't feed nicely, the biggest issue is that it is badly wound on the spool so somehow it gets slightly jammed, leading to small gaps in the printing. I have upped the current for the filament stepper which helps and has reduced this to a minor cosmetic issue (I was junking parts before solving the problem) but I am still having to keep an eye on the filament for potential jams - just cleared one. I'm doing an 18-hour part so this is a PITA, although its big enough and of a nature where I can stop the print, re slice with the bottom taken off and epoxy the parts together - I did this with the matching part as I suffered a broken thermistor wire, so the print stopped, followed by two more stops as the solder joint melted, then my crimp connection broke and I then eventually got a new thermistor. The part was in five pieces (the final stop was after it had branched into two parts). Fortunately the z-height is very accurate so a vernier reading of print height, then crop the bottom off gives two parts that match OK.

Yeah I understand they're a small company and probably never anticipated so many people wanting this beefier version of the I3. I'll look on it as a means of adding diversity to our printer users!

That's unfortunate about the spooling inconsistency. Not really experienced in this field yet but could it be a temperature stability issue? The more heat might help the gooey plastic to lubricate it's way through the tubes.

I know that with injection moulded thermo-plastics which are a whole different animal but with those, when recycling nylon, you need a lot of heat and pressure to get it to shift.

Michael W

Edited By Michael-w on 19/05/2017 12:17:03

PS, might wanna check this out Neil, if the extruder feed is giving you trouble;

This is an upgraded version of the stepper extruder head used on the prusa I3, and although it is intended for the one I bought, they claim it can work with most reprap machines.

**LINK**

I paraphrase in sintrons own words;

"The extruder is the most important part of a 3d printer, and also the most difficult to calibrate, we have made necessary design to prevent "jammed" problem. I cant emphasize how important this is and other sellers don't have this and would cause many problems....

The MK8 extruder is open source universal suitable for most reprap and DIY long distance feeding filament 3D printers"

Michael W

Edited By Michael-w on 19/05/2017 13:07:41

+ one for the Sintron. Transformed my old Mendel90 when coupled with an E3D head. As previous be cautious about too much retract, especially if running a Bowden tube (which was also a big improvement in the lightly built Mendel90). - No connection with either party, just a contented client.

Theres also some bowden tubing sold here if you do consider that head..

**LINK**

Or this one comes with the "hot end" head as well as a tube. 

http://www.ebay.co.uk/itm/Hotend-J-head-All-Metal-Bowden-extruder-For-Makerbot-Reprap-3D-printer-parts-/131807680763?var=&hash=item1eb05998fb:m:mXauTMFkUxY9tBYvJwbiBew

Michael W

Edited By Michael-w on 19/05/2017 14:29:35

Has anyone on here had a look at, or use, the Fisher Delta 3D printer. They were on a stand at the Doncaster show last weekend. The build quality looked good (to me) but it was not printing at the time.

Wondering how the Delta type of printer compares to the Prusa i3.

Thanks,

Colin

I bought one at the Warwick show, last year. Been ok, but took some fetling. They are only as good as the build!

Not sure if I would buy the same again, ( it was £350). But the "delta" design is quite a good one.

Whatever you get, NEVER, NEVER buy cheap filament, use a trusted supplier.....

I already have a Mk 8 head, looks identical to that one (most don't have that little thumb tab on the end).

Apparently there's now a MK9 available.

My problem's haven't been with the head (aside from needing an extra guide put in to get flexible filament to work.

It's worth googling '#filaween' for an overview of 30 different filaments. That chap found price didn't seem to be a big issue when it came to print quality.

Accurately measuring the filament diameter and tuning the temperature/retraction settings DOES seem to make a difference.

IP/Wi-Fi camera can be handy for keeping an eye on a printer when you can't be beside it to baby-sit.

You mean I could watch it on the computer without having to look over my left shoulder

N.

I guess it is the modern alternative to "Watching paint dry" ?
BobH

It's strangely hypnotic. Cura chooses some rather odd sequences sometimes and you end up following what it's doing on a complex part and you discover ten or fifteen minutes have gone past.

Neil

Well at least you wouldn't get severe neck or thorax syndrome (SNOTS as it's called in medical speak).